基于视觉掩蔽的隐写不可感知性评价方法

传统的信息隐藏不可感知性评价方法不能全面反映人眼主观感受,以致无法准确衡量隐藏算法的性能。为此,利用人眼感知质量与图像自身均方误差呈线性关系的特点,同时考虑人眼对亮度和纹理的敏感特性,提出一种基于视觉掩蔽的评价方法。给出图像感知质量与图像均方误差之间的线性表达式,根据亮度表达式和梯度分别计算亮度权重系数和纹理权重系数,运用计算所得的权重系数对线性表达式进行线性加权,得到隐写不可感知性评价值。实验结果表明,与峰值信噪比方法相比,该方法得出的评价结果能更准确地反映主观感知质量。

Imperceptibility Evaluation Method of Steganography Based on Visual Masking

The commonly-used methods of imperceptibility evaluation for information hiding algorithms can not express the subjective evaluation comprehensively and evaluate the performance of the algorithms accurately. To solve this problem,a new method based on visual masking is proposed. It combines the linear relationship between the perceptual quality of image and its Mean Square Error（MSE）,and the perceptual properties of texture and luminance,with the aim of improving the perceptual quality. In this method,the linear expression between the perceptual quality and MSE is given,among which the luminance and the gradient can be used to calculate the luminance and the texture weight coefficients respectively. By weighting the expression linearly,a global performance of imperceptibility of the stego image is obtained. Experimental results demonstrate that the proposal outperforms the conventional Peak Signal to Noise Ratio（PSNR）in higher efficiency and realizing the consistency of image quality of subjective and objective evaluation.